The performance of resisting foundation displacement of a typical single return circuit transmission tower under all kinds of load conditions including foundation horizontal displacement, foundation vertical uneven downward displacement was analyzed by finite element modeling. Results showed that stability failure of single steel angle represents tower’s limit state under foundation displacement. And the corresponding foundation displacement limits were calculated. Results indicate that foundation pull condition is more dangerous than press condition. Under complex foundation displacement conditions, foundation horizontal displacement is primary factor leading to stability failure of towers. Under foundation press condition and pull condition, wind load is primary factor. Result also indicates that, tower does not fail when foundation displacements are smaller than 1.25% (under foundation press condition and pull condition) or 0.5% (under single foundation sink condition) of tower root distance.